A new modulation scheme of 256-quadrature amplitude modulation (256-QAM) is introduced for downlink transmissions in third generation partnership project (3GPP) long-term evolution (LTE) networks. This new modulation scheme may increase spectral efficiency as compared to incumbent modulation schemes such as quadrature phase shift keying (QPSK), 16-QAM, and 64-QAM, but may complicate interworking of legacy and advanced user equipments (UEs).